Selective removal of cesium and strontium using porous frameworks from high level nuclear waste

Abstract

Efficient and cost-effective removal of radioactive ¹³⁷Cs and ⁹⁰Sr found in spent fuel is an important step for safe, long-term storage of nuclear waste. Solid-state materials such as resins and titanosilicate zeolites have been assessed for the removal of Cs and Sr from aqueous solutions, but there is room for improvement in terms of capacity and selectivity. Herein, we report the Cs⁺ and Sr²⁺ exchange potential of an ultra stable MOF, namely, MIL-101-SO₃H, as a function of different contact times, concentrations, pH levels, and in the presence of competing ions. Our preliminary results suggest that MOFs with suitable ion exchange groups can be promising alternate materials for cesium and strontium removal.